Master rolls are trimmed (i.e., cut) to produce multiple product and/or standard rolls. Product rolls are produced to fill customer orders. Standard rolls have widths and diameters that are frequently requested by customers and that are produced on speculation that customers will order rolls in those widths and diameters.
The orders for product rolls from different customers have different specifications. Thus, it is desirable to form cutting patterns that minimize cutting losses while at the same time meeting the specifications of each customer. When the ordered widths exceed half of the width of the master roll from which the product rolls are cut, trim efficiency, even trim efficiency obtained from algorithms that optimize trim efficiency, can be very low. For example, if all of the sizes ordered by customers exceed half the width of the master rolls, the trim loss obtained by using trimming algorithms is poor and, in worst case, can approach 49%.
This waste can be reduced by creating auxiliary (i.e., intermediate) rolls from the excess width trimmed off of the master rolls and then by edge-wise joining the material of these auxiliary rolls to form wider rolls to meet the ordered widths. This process of combining rolls of smaller widths to form rolls of larger widths is termed “skiving.” Thus, skiving is used to join two or more auxiliary rolls to produce a skived roll.
Customer demand for product rolls, then, can be filled from the master roll directly and also from the skived rolls that are created by skiving.
When several auxiliary rolls are available, the objective of skiving should be to minimize the overall trim loss. Hence, skiving and trimming can be viewed as counter parts of the optimization problem, and can be analyzed and modeled in a combined optimization system to minimize trim loss by generating auxiliary rolls which will be later joined to produce ordered (and/or standard) width rolls. This optimization system may be based on a mathematical model that solves the skiving and trimming problems jointly to improve trim efficiency.
The present invention is directed to a system and/or method that solves one or more of the above stated or other problems and/or that combines skiving and trimming solutions in order to increase trimming efficiency.